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authorPavan Kunapuli <pkunapuli@nvidia.com>2015-01-28 11:45:16 -0500
committerUlf Hansson <ulf.hansson@linaro.org>2015-01-29 11:21:58 +0100
commit352ee868dda03ca72e60d4853356881ff161ec23 (patch)
tree67cfefe825be4832549c896202cb3c8aedee3403
parent0501be6429e4eb02f417ad83eacd84b8c57b0283 (diff)
downloadkernel-352ee868dda03ca72e60d4853356881ff161ec23.tar.gz
mmc: tegra: Write xfer_mode, CMD regs in together
If there is a gap between xfer mode and command register writes, tegra SDMMC controller can sometimes issue a spurious command before the CMD register is written. To avoid this, these two registers need to be written together in a single write operation. This is implemented as an NVQUIRK as it applies to T114, T124 and T132. Signed-off-by: Pavan Kunapuli <pkunapuli@nvidia.com> Signed-off-by: Rhyland Klein <rklein@nvidia.com> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
-rw-r--r--drivers/mmc/host/sdhci-tegra.c30
1 files changed, 29 insertions, 1 deletions
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 59797106af93..f3778d58d1cd 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -41,6 +41,7 @@
#define NVQUIRK_DISABLE_SDR50 BIT(3)
#define NVQUIRK_DISABLE_SDR104 BIT(4)
#define NVQUIRK_DISABLE_DDR50 BIT(5)
+#define NVQUIRK_SHADOW_XFER_MODE_REG BIT(6)
struct sdhci_tegra_soc_data {
const struct sdhci_pltfm_data *pdata;
@@ -67,6 +68,31 @@ static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
return readw(host->ioaddr + reg);
}
+static void tegra_sdhci_writew(struct sdhci_host *host, u16 val, int reg)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_tegra *tegra_host = pltfm_host->priv;
+ const struct sdhci_tegra_soc_data *soc_data = tegra_host->soc_data;
+
+ if (soc_data->nvquirks & NVQUIRK_SHADOW_XFER_MODE_REG) {
+ switch (reg) {
+ case SDHCI_TRANSFER_MODE:
+ /*
+ * Postpone this write, we must do it together with a
+ * command write that is down below.
+ */
+ pltfm_host->xfer_mode_shadow = val;
+ return;
+ case SDHCI_COMMAND:
+ writel((val << 16) | pltfm_host->xfer_mode_shadow,
+ host->ioaddr + SDHCI_TRANSFER_MODE);
+ return;
+ }
+ }
+
+ writew(val, host->ioaddr + reg);
+}
+
static void tegra_sdhci_writel(struct sdhci_host *host, u32 val, int reg)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -147,6 +173,7 @@ static void tegra_sdhci_set_bus_width(struct sdhci_host *host, int bus_width)
static const struct sdhci_ops tegra_sdhci_ops = {
.get_ro = tegra_sdhci_get_ro,
.read_w = tegra_sdhci_readw,
+ .write_w = tegra_sdhci_writew,
.write_l = tegra_sdhci_writel,
.set_clock = sdhci_set_clock,
.set_bus_width = tegra_sdhci_set_bus_width,
@@ -201,7 +228,8 @@ static struct sdhci_tegra_soc_data soc_data_tegra114 = {
.pdata = &sdhci_tegra114_pdata,
.nvquirks = NVQUIRK_DISABLE_SDR50 |
NVQUIRK_DISABLE_DDR50 |
- NVQUIRK_DISABLE_SDR104,
+ NVQUIRK_DISABLE_SDR104 |
+ NVQUIRK_SHADOW_XFER_MODE_REG,
};
static const struct of_device_id sdhci_tegra_dt_match[] = {